The invention relates to monitor systems for agricultural equipment, and, more specifically, to a monitor system for assisting in the formation of large cylindrical bales of a substantially uniform diameter over their length.
Balers for the formation of large, cylindrical bales of crop material are well known and widely used throughout the agricultural industry. The bales, which typically are six feet in diameter and five feet long, are formed inside a tractor-drawn baler which picks up windrowed crop material off of the ground. The crop material is fed into a baling chamber formed by a plurality of endless belts which roll the crop material into the large cylindrical bales.
Important to the formation of bales of uniform diameter is a substantially even distribution of crop material over the entire width of the baler. If the windrow is other than substantially the full width of the baler and of uniform height across the width of the windrow, crop material may be nonuniformly distributed across the length of the bale, resulting in uneven bales. For example, if the windrow is narrower than the baler and is fed down the center of the crop pick up of the baler, a barrel-shaped bale may result. If crop material was fed into one side of the baler preferentially over the other side of the baler, a bale having a conical section may result.
An approach that has been taken to make the bales of a more uniform diameter is to drive the baler to direct crop material alternately to the opposite sides of the crop pick up means. For example, by driving a sinusoidal path the crop material will be directed to both ends of the bale as well as to the middle of the bale. Accordingly, bale monitors have been developed which direct the operator of the baler to drive the baler in a pattern which will result in uniform bales. For example, U.S. Pat. Nos. 4,517,795 and 4,224,867 teach a pair of sensor arms which ride on one of the endless belts at either side of the baler. The sensor arms are connected to a monitor box mounted adjacent the operator. The monitor box detects when belt tension at one side of the baler is greater than the other side and directs the operator to steer the baler to add crop material to the side of the baler where belt tension is less.
Another system is described in U.S. Pat. No. 4,742,768 where a belt tensioning arm, which pivots as the forming bale increases in diameter, controls a monitor that is responsive to changes in bale diameter. The monitor is mounted near the operator and will direct the operator to steer the baler so as to add crop material to an opposite side of the baler alternately in correspondence with predetermined movement of the arm.
Yet another patent, U.S. Pat. No. 4,702,066, describes a pair of belt tension sensing arms located at either side of the baler for monitoring the belt tension in the endless belts at the end portions of the forming bale. When the belt tension at one end of the baler substantially exceeds that at the other end, a signal is sent to a control system for steering the wheels of the baler to direct the baler so that crop material preferentially fills the side of the baler with less belt tension. No action is required of the operator, as the baler itself weaves to assure that a bale of uniform diameter is formed.
Existing bale monitor systems, accordingly, either monitor the relative tension in belts located of the baler to infer bale diameter at either end of the forming bale, or they monitor directly the bale diameter at either end of the forming bale. In the present invention, a system for monitoring the volume of crop material entering the baler includes an interval timer of adjustable period which controls a monitor box mounted near the operator. The monitor box signals to the operator to direct crop material to alternate sides of the baler, oscillating from one side to the other at a preselected, adjustable time interval. The timer is interrupted during periods in which crop material is not entering the baler so that the monitor system is responsive to the volume of crop material entering the baler. In a second preferred embodiment, the timer controls a system for steering directly the wheels of the baler. According to the present invention, no actual sensing or measurement of bale diameter or belt tension is made.